Producing hydrocarbons from a rock formation often requires stimulation of the rock formation, especially for rock formations of low permeability. A stimulation process may include pumping a specially designed stimulation fluid into a wellbore within the rock formation at a pressure that is high enough for the stimulation fluid to sufficiently infiltrate and react with the rock formation to cause a fracture in the rock formation. In some examples, consecutive stages (for example, axial sections) of the rock formation are stimulated serially in a process known as multi-stage fracturing. In a multi-stage fracturing process, each stage of the rock formation is fluidically isolated from an adjacent downstream stage while being stimulated. A commonly occurring problem in multi-stage fracturing processes is failure of fluidic isolation of adjacent stages (for example, isolation failure), such that stimulation fluid introduced to a target stage leaks into an adjacent downstream stage that has already been stimulated. Leakage of the stimulation fluid into the adjacent stage results in a drop in fluid pressure at the target stage such that the stimulation fluid can no longer sufficiently infiltrate the rock formation to cause adequate fracturing in the formation at the target stage. Isolation failure within a wellbore can result in cancellation of a stimulation process, a prolonged time period for completing stimulation at a target stage (for example, including repeating stimulation at an adjacent downstream stage), and/or undesirable modifications to stimulation fluid volumes and stimulation fluid pumping rates within the wellbore.